Automatic viewport display synchronization during application sharing

Abstract

A method and apparatus for synchronizing the display of the output of one or more applications being shared on participating host and guest computers, where the respective areas available for display of the output are unequal. In one embodiment, the host or a guest may alter the output display on the monitor's of all other guest participants. The host issues a command receivable by participating guests to alter the displayed output on the guest monitors corresponding to display output surrounding a point movable within the output display on the host monitor. A guest wishing to alter the output display on other guest monitors issues a request receivable by the host which in turn issues a command to all guests to update their output displays. The guests can be instructed to update the displays on their monitors to display output surrounding a point, movable under control of the requesting guest, within the output displayed on the requesting guest's monitor. In another embodiment, the output displayed on a guest monitor is updated automatically, as a shared cursor is moved from the boundary of the output displayed on the guest monitor.

What we claim is: 
     
       1. A computer implemented method for the sharing of one or more applications by a host and a first guest, the first guest having a guest viewport on a guest video monitor, the host having a host viewport on a host video monitor, the one or more applications generating an output display on the viewports of the host and the first guest, the method comprising the steps of: (a) tracking, with the computer, the position of a shared cursor on the video monitor of the first guest; and   (b) automatically adjusting with the computer, in accordance with said tracking, the output display of the viewport of the first guest as necessary to maintain a desired portion of the output display within the viewport of the first guest, wherein the automatic adjusting does not require input of a human user of the first guest.   
     
     
       2. The method of claim 1, wherein step (b) comprises the step of adjusting the output display of the viewport of the first guest to maintain the shared cursor within the viewport of the first guest. 
     
     
       3. The method of claim 1, wherein the shared cursor mimics movement of a host cursor in the host viewport and step (a) comprises the step of tracking the position of the shared cursor as it mimics the movement of the host cursor. 
     
     
       4. The method of claim 1, wherein a host cursor in the host viewport mimics movement of the shared cursor by the first guest and step (a) comprises the step of tracking the position of the shared cursor as it is being moved by the first guest. 
     
     
       5. The method of claim 1, wherein there is a second guest viewport having a second guest cursor and the shared cursor mimics movement of the second guest cursor, and step (a) comprises the step of tracking position of the shared cursor as it mimics the movement of the second guest cursor. 
     
     
       6. The method of claim 1, wherein a point is generated in the host viewport, the point being movable by the host within the output display on the host viewport, wherein step (b) comprises the step of adjusting the output display of the viewport of the first guest to include output display on the host viewport near the point. 
     
     
       7. The method of claim 6, wherein there are plural guest viewports, and step (b) comprises the step of adjusting the output display of the plural guest viewports to include output display on the host viewport near the point. 
     
     
       8. The method of claim 1, wherein there is a second guest viewport and a point is generated in the second guest viewport, the point being movable within the output display on the second guest viewport, and step (b) comprises the step of adjusting the output display on the first guest viewport to include output display near the point. 
     
     
       9. The method of claim 8, wherein step (b) comprises the step of adjusting the output display on the first guest viewport according to a command received from the host. 
     
     
       10. The method of claim 9, wherein the command is issued by the host in response to a request by the second guest for the host to issue the command. 
     
     
       11. The method of claim 1, wherein: step (a) comprises the step of tracking the position of the shared cursor within a pan window on the video monitor of the first guest, the pan widow representing the host viewport; and   further comprising the step of generating a point in the pan window, the point being movable by the first guest to identify a section of the output display on the host viewport; and   step (b) comprises the step of adjusting the output display of the viewport of the first guest to include the identified section.   
     
     
       12. The method of claim 11, wherein there are plural guest viewports and step (b) comprises the step of adjusting the output display of the plural guest viewports to include the identified section. 
     
     
       13. An apparatus for the sharing of one or more applications by a host and a first guest, the first guest having a guest viewport on a guest video monitor, the host having a host viewport on a host video monitor, the one or more applications generating an output display on the viewports of the host and the first guest, comprising: (a) means for tracking, with a computer, the position of a shared cursor on the video monitor of the first guest; and   (b) means for automatically adjusting with the computer, in accordance with said tracking, the output display of the viewport of the first guest as necessary to maintain a desired portion of the output display within the viewport of the first guest, wherein the automatic adjusting does not require input of a human user of the first guest.   
     
     
       14. The apparatus of claim 13, wherein means (b) adjusts the output display of the viewport of the first guest to maintain the shared cursor within the viewport of the first guest. 
     
     
       15. The apparatus of claim 13, wherein there is a second guest viewport and a point is generated in the second guest viewport, the point being movable within the output display on the second guest viewport, and means (b) adjusts the output display on the first guest viewport to include output display near the point. 
     
     
       16. The apparatus of claim 13, wherein: means (a) tracks the position of the shared cursor within a pan window on the video monitor of the first guest, the pan widow representing the host viewport; and   further comprising means for generating a point in the pan window, the point being movable by the first guest to identify a section of the output display on the host viewport; and   means (b) adjusts the output display of the viewport of the first guest to include the identified section.   
     
     
       17. A storage medium encoded with machine-readable computer program code for the sharing of one or more applications by a host and a first guest, the first guest having a guest viewport on a guest video monitor, the host having a host viewport on a host video monitor, the one or more applications generating an output display on the viewports of the host and the first guest, comprising: (a) means for causing a computer to track the position of a shared cursor on the video monitor of the first guest; and   (b) means for causing the computer to automatically adjust, in accordance with said tracking, the output display of the viewport of the first guest as necessary to maintain a desired portion of the output display within the viewport of the first guest, wherein the automatic adjusting does not require input of a human user of the first guest.   
     
     
       18. The storage medium of claim 17, wherein means (b) causes the computer to adjust the output display of the first guest to maintain the shared cursor within the viewport of the first guest. 
     
     
       19. The storage medium of claim 17, wherein there is a second guest viewport and a point is generated in the second guest viewport, the point being movable within the output display on the second guest viewport, and means (b) causes the computer to adjust the output display on the first guest viewport to include output display near the point. 
     
     
       20. The storage medium of claim 17, wherein: means (a) causes the computer to track the position of the shared cursor within a pan window on the video monitor of the first guest, the pan widow representing the host viewport; and   further comprising means for causing the computer to generate a point in the pan window, the point being movable by the first guest to identify a section of the output display on the host viewport; and   means (b) causes the computer to adjust the output display of the viewport of the first guest to include the identified section.